Search results for "uce"
showing 10 items of 2599 documents
(H,ρ)-induced dynamics and large time behaviors
2018
In some recent papers, the so called (H,ρ)-induced dynamics of a system S whose time evolution is deduced adopting an operatorial approach, borrowed in part from quantum mechanics, has been introduced. Here, H is the Hamiltonian for S, while ρ is a certain rule applied periodically (or not) on S. The analysis carried on throughout this paper shows that, replacing the Heisenberg dynamics with the (H,ρ)-induced one, we obtain a simple, and somehow natural, way to prove that some relevant dynamical variables of S may converge, for large t, to certain asymptotic values. This cannot be so, for finite dimensional systems, if no rule is considered. In this case, in fact, any Heisenberg dynamics im…
Photoluminescence-Based Spatially Resolved Temperature Coefficient Maps of Silicon Wafers and Solar Cells
2020
In this article, we present a method to obtain implied open-circuit voltage images of silicon wafers and cells at different temperatures. The proposed method is then demonstrated by investigating the temperature coefficients of various regions across multicrystalline silicon wafers and cells from different heights of two bricks with different dislocation densities. Interestingly, both low and high temperature coefficients are found in dislocated regions on the wafers. A large spread of temperature coefficient is observed at regions with similar performance at 298 K. Reduced temperature sensitivity is found to be correlated with the increasing brick height and is exhibited by both wafers and…
A Novel Method for Characterizing Temperature Sensitivity of Silicon Wafers and Cells
2019
In this paper, we present a novel method to obtain temperature dependent lifetime and implied-open-circuit voltage (iV OC ) images of silicon wafers and solar cells. First, the method is validated by comparing the obtained values with global values acquired from lifetime measurements (for wafers) and current-voltage measurements (for cells). The method is then extended to acquire spatially resolved images of iV OC temperature coefficients of silicon wafers and cells. Potential applications of the proposed method are demonstrated by investigating the temperature coefficients of various regions across multi-crystalline silicon wafers and cells from different heights of two bricks with differe…
Experimental investigation on different rainfall energy harvesting structures
2018
In this paper proposes an experimental comparison between different rainfall harvesting devices and the study of the corresponding electrical rectifying circuit. More in detail, three harvesting structures are considered: the cantilever, the bridge and the floating circle. For each of the proposed structure, different waveforms have been acquired and discussed. The processed data have been compared in order to suggest the best choice for the rectifying circuit, from the simplest one to the most endorsed in the technical literature.
Reduced temperature sensitivity of multicrystalline silicon solar cells with low ingot resistivity
2016
This study presents experimental data on the reduction of temperature sensitivity of multicrystalline silicon solar cells made from low resistivity ingot. The temperature coefficients of solar cells produced from different ingot resistivities are compared, and the advantages of increasing the net doping are explained.
Measuring rain energy with the employment of “Arduino”
2016
This paper presents the performances of rainfall energy harvesting through the use of a piezoelectric transducer and an Arduino-based measuring system. Diverse studies agree on the possibility of generating electricity from rainfall, but to date, a study that can measure the quantity of energy produced during rainfall is still missing. The present study begins with results obtained from laboratory researchers using piezoelectric transducers and oscilloscopes — to measure the energy produced from a single raindrop — and concludes with an ad hoc Arduino-based measuring system, aimed at measuring the actual amount of electrical energy produced by a piezoelectric transducer that is exposed to r…
Measurement of the activation energies of oxygen ion diffusion in yttria stabilized zirconia by flicker noise spectroscopy
2019
The low-frequency noise in a nanometer-sized virtual memristor consisting of a contact of a conductive atomic force microscope (CAFM) probe to an yttria stabilized zirconia (YSZ) thin film deposited on a conductive substrate is investigated. YSZ is a promising material for the memristor application since it is featured by high oxygen ion mobility, and the oxygen vacancy concentration in YSZ can be controlled by varying the molar fraction of the stabilizing yttrium oxide. Due to the low diameter of the CAFM probe contact to the YSZ film (similar to 10nm), we are able to measure the electric current flowing through an individual filament both in the low resistive state (LRS) and in the high r…
Gold(II) Porphyrins in Photoinduced Electron Transfer Reactions
2019
Chemistry - a European journal 25(23), 5940 - 5949 (2019). doi:10.1002/chem.201900050
Cover Picture: Dynamic Chemical Devices: Photoinduced Electron Transfer and Its Ion-Triggered Switching in Nanomechanical Butterfly-Type Bis(porphyri…
2006
Light-Induced Alkylation of (Hetero)aromatic Nitriles in a Transition-Metal-Free C–C-Bond Metathesis
2017
A light-induced C–C-σ-bond metathesis was achieved through transition-metal-free activation of an unstrained C(sp3)–C(sp3)-σ-bond in 1-benzyl-1,2,3,4-tetrahydroisoquinolines. A photoredox-mediated single-electron oxidation of these precursor amines yield radical cations which undergo a homolytic cleavage of a C(sp3)–C(sp3)-σ-bond rather than the well-known α-C–H-scission. The resulting carbon-centered radicals are used in the ipso-substitution of (hetero)aromatic nitriles proceeding through another single-electron transfer-mediated C–C-bond cleavage and formation.